Publications

The COVID-19 pandemic has led to extensive morbidity and mortality throughout the world. Clinical features that drive SARS-CoV-2 pathogenesis in humans include inflammation and thrombosis, but the mechanistic details underlying these processes remain to be determined. In this study, we demonstrate endothelial disruption and vascular thrombosis in histopathologic sections of lungs from both humans and rhesus macaques infected with SARS-CoV-2. To define key molecular pathways associated with SARS-CoV-2 pathogenesis in macaques, we performed transcriptomic analyses of bronchoalveolar lavage and peripheral blood and proteomic analyses of serum. We observed macrophage infiltrates in lung and upregulation of macrophage, complement, platelet activation, thrombosis, and proinflammatory markers, including C-reactive protein, MX1, IL-6, IL-1, IL-8, TNFα, and NF-κB. These results suggest a model in which critical interactions between inflammatory and thrombosis pathways lead to SARS-CoV-2-induced vascular disease. Our findings suggest potential therapeutic targets for COVID-19.

BACKGROUND: The choroid plexus is a major contributor to the generation of cerebrospinal fluid (CSF) and the maintenance of its electrolyte and metabolite balance. Here, we sought to characterize the blood flow dynamics of the choroid plexus using arterial spin labeling (ASL) MRI to establish ASL as a non-invasive tool for choroid plexus function and disease studies.

METHODS: Seven healthy volunteers were imaged on a 3T MR scanner. ASL images were acquired with 12 labeling durations and post labeling delays. Regions of the choroid plexus were manually segmented on high-resolution T1 weighted images. Choroid plexus perfusion was characterized with a dynamic ASL perfusion model. Cerebral gray matter perfusion was also quantified for comparison.

RESULTS: Kinetics of the ASL signal were clearly different in the choroid plexus than in gray matter. The choroid plexus has a significantly longer T1 than the gray matter (2.33 ± 0.30 s vs. 1.85 ± 0.10 s, p < 0.02). The arterial transit time was 1.24 ± 0.20 s at the choroid plexus. The apparent blood flow to the choroid plexus was measured to be 39.5 ± 10.1 ml/100 g/min and 0.80 ± 0.31 ml/min integrated over the posterior lateral ventricles in both hemispheres. Correction with the choroid plexus weight yielded a blood flow of 80 ml/100 g/min.

CONCLUSIONS: Our findings suggest that ASL can provide a clinically feasible option to quantify the dynamic characteristics of choroid plexus blood flow. It also provides useful reference values of the choroid plexus perfusion. The long T1 of the choroid plexus may suggest the transport of water from arterial blood to the CSF, potentially providing a method to quantify CSF generation.

Transcranial magnetic stimulation (TMS) reveals decreased efficacy of long-term potentiation-like (LTP-like) neuroplastic mechanisms in Alzheimer's disease (AD). However, it is not yet known whether LTP-like plasticity is also impaired in prodromal AD, or how abnormal TMS measures are related to established AD biomarkers. Here, we investigated the LTP-like response to intermittent theta-burst stimulation in 17 amyloid-positive participants with amnestic mild cognitive impairment (MCI) and 10 cognitively unimpaired controls. Our results showed a lack of LTP-like neuromodulation in MCI compared with controls that was unrelated to quantitative amyloid-beta burden on positron emission tomography. Surprisingly, greater LTP-like response was related to worse memory function in the MCI group, highlighting the complex role of neuroplasticity in the prodromal stages of AD. Overall, our results demonstrate abnormal LTP-like plasticity using intermittent theta-burst stimulation assessment in amyloid-positive participants with MCI. These findings support the potential for development of TMS measures as prognostic markers or therapeutic targets in early-stage symptomatic AD.

This article presents a current snapshot in time, describing how radiology departments around the country are planning recovery from the baseline of the coronavirus disease 2019 pandemic, with a focus on different domains of recovery such as managing appointment availability, patient safety and workflow changes, and operational data and analytics. An e-mail survey was sent through the Society of Chairs of Academic Radiology Departments list server to 114 academic radiology departments. On the basis of data reported by the 38 survey respondents, best practices and shared experience are described for three key areas: (1) planning for recovery, (2) creating a new normal, and (3) measuring and forecasting. Radiology practices should be aware of the common approaches and preparations academic radiology departments have taken to reopening imaging in the post-coronavirus disease 2019 world. This should all be done when maintaining a safe and patient-centric environment and preparing to minimize the impact of future outbreaks or pandemics.

Background Confirming that subsolid adenocarcinomas show exponential growth is important because it would justify using volume doubling time to assess their growth. Purpose To test whether the growth of lung adenocarcinomas manifesting as subsolid nodules at chest CT is accurately represented by an exponential model. Materials and Methods Patients with lung adenocarcinomas manifesting as subsolid nodules surgically resected between January 2005 and May 2018, with three or more longitudinal CT examinations before resection, were retrospectively included. Overall volume (for all nodules) and solid component volume (for part-solid nodules) were measured over time. A linear mixed-effects model was used to identify the growth pattern (linear, exponential, quadratic, or power law) that best represented growth. The interactions between nodule growth and clinical, CT morphologic, and pathologic parameters were studied. Results Sixty-nine patients (mean age, 70 years ± 9 [standard deviation]; 48 women) with 74 lung adenocarcinomas were evaluated. Overall growth and solid component growth were better represented by an exponential model (adjusted R2 = 0.89 and 0.95, respectively) than by a quadratic model (r2 = 0.88 and 0.93, respectively), a linear model (r2 = 0.87 and 0.92, respectively), or a power law model (r2 = 0.82 and 0.93, respectively). Faster overall volume growth was associated with a history of lung cancer (P < .001), a baseline nodule volume less than 500 mm3 (P = .03), and histologic findings of invasive adenocarcinoma (P < .001). The median volume doubling time of noninvasive adenocarcinoma was significantly longer than that of invasive adenocarcinoma (939 days [interquartile range, 588-1563 days] vs 678 days [interquartile range, 392-916 days], respectively; P = .01). Conclusion The overall volume growth of adenocarcinomas manifesting as subsolid nodules at chest CT was best represented by an exponential model compared with the other tested models. This justifies the use of volume doubling time for the growth assessment of these nodules. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Kuriyama and Yanagawa in this issue.

INTRODUCTION: Guidelines recommend individualized breast cancer screening and prevention interventions for women in their 40s. Yet, few primary care clinicians assess breast cancer risk.

STUDY DESIGN: Pretest-Posttest trial.

SETTING/PARTICIPANTS: Women aged 40-49 years were recruited from one large Boston-based academic primary care practice between July 2017 and April 2019.

INTERVENTION: Participants completed a pretest, received a personalized breast cancer risk report, saw their primary care clinician, and completed a posttest.

MAIN OUTCOME MEASURES: Using mixed effects models, changes in screening intentions (0-100 scale [0=will not screen to 100=will screen]), mammography knowledge, decisional conflict, and receipt of screening were examined. Analyses were conducted from June 2019 to February 2020.

RESULTS: Patient (n=337) mean age was 44.1 (SD=2.9) years, 61.4% were non-Hispanic white, and 76.6% were college graduates; 306 (90.5%) completed follow-up (203 with 5-year breast cancer risk <1.1%). Screening intentions declined from pre- to post-visit (79.3 to 68.0, p<0.0001), especially for women with 5-year risk <1.1% (77.2 to 63.3, p<0.0001), but still favored screening. In the 2 years prior, 37.6% had screening mammography compared with 41.8% over a mean 16 months follow-up (p=0.17). Mammography knowledge increased and decisional conflict declined. Eleven (3.3%) women met criteria for breast cancer prevention medications (ten discussed medications with their clinicians), 22 (6.5%) for MRI (19 discussed MRI with their clinician), and 67 (19.8%) for genetic counseling (47 discussed with the clinician).

CONCLUSIONS: Receipt of a personalized breast cancer report was associated with women in their 40s making more-informed and less-conflicted mammography screening decisions and with high-risk women discussing breast cancer prevention interventions with clinicians.

TRIAL REGISTRATION: This study is registered at www.clinicaltrials.govNCT03180086.

The aim of this study was to develop and test multiclass predictive models for assessing the invasiveness of individual lung adenocarcinomas presenting as subsolid nodules on computed tomography (CT). 227 lung adenocarcinomas were included: 31 atypical adenomatous hyperplasia and adenocarcinomas in situ (class H1), 64 minimally invasive adenocarcinomas (class H2) and 132 invasive adenocarcinomas (class H3). Nodules were segmented, and geometric and CT attenuation features including functional principal component analysis features (FPC1 and FPC2) were extracted. After a feature selection step, two predictive models were built with ordinal regression: Model 1 based on volume (log) (logarithm of the nodule volume) and FPC1, and Model 2 based on volume (log) and Q.875 (CT attenuation value at the 87.5% percentile). Using the 200-repeats Monte-Carlo cross-validation method, these models provided a multiclass classification of invasiveness with discriminative power AUCs of 0.83 to 0.87 and predicted the class probabilities with less than a 10% average error. The predictive modelling approach adopted in this paper provides a detailed insight on how the value of the main predictors contribute to the probability of nodule invasiveness and underlines the role of nodule CT attenuation features in the nodule invasiveness classification.

BACKGROUND: Arterial Spin Labeling (ASL) MRI can provide quantitative images that are sensitive to both time averaged blood flow and its temporal fluctuations. 3D image acquisitions for ASL are desirable because they are more readily compatible with background suppression to reduce noise, can reduce signal loss and distortion, and provide uniform flow sensitivity across the brain. However, single-shot 3D acquisition for maximal temporal resolution typically involves degradation of image quality through blurring or noise amplification by parallel imaging. Here, we report a new approach to accelerate a common stack of spirals 3D image acquisition by pseudo golden-angle rotation and compressed sensing reconstruction without any degradation of time averaged blood flow images.

METHODS: 28 healthy volunteers were imaged at 3T with background-suppressed unbalanced pseudo-continuous ASL combined with a pseudo golden-angle Stack-of-Spirals 3D RARE readout. A fully-sampled perfusion-weighted volume was reconstructed by 3D non-uniform Fast Fourier Transform (nuFFT) followed by sum-of-squares combination of the 32 individual channels. Coil sensitivities were estimated followed by reconstruction of the 39 single-shot volumes using an L1-wavelet Compressed-Sensing reconstruction. Finally, brain connectivity analyses were performed in regions where BOLD signal suffers from low signal-to-noise ratio and susceptibility artifacts.

RESULTS: Image quality, assessed with a non-reference 3D blurring metric, of full time averaged blood flow was comparable to a conventional interleaved acquisition. The temporal resolution provided by the acceleration enabled identification and quantification of resting-state networks even in inferior regions such as the amygdala and inferior frontal lobes, where susceptibility artifacts can degrade conventional resting-state fMRI acquisitions.

CONCLUSION: This approach can provide measures of blood flow modulations and resting-state networks for free within any research or clinical protocol employing ASL for resting blood flow.

OBJECTIVE: To evaluate gender and racial profiles of US academic radiology faculty.

MATERIALS AND METHODS: This is a retrospective analysis of the American Association of Medical College database of radiology faculty members from 2006 to 2017 by academic rank, chair position, race or ethnicity, and gender. The data were described with annual proportions and average annual counts and fit to a Poisson regression model. Comparison data were taken from American Association of Medical College on matriculants at US medical schools and from ACGME on radiology residents.

RESULTS: Women increased significantly in the ranks of professor by 4.5%, associate professor by 4.8%, and assistant professor by 4.8% (P < .05). Asian and multiple race non-Hispanic radiologists increased in the rank of professor by 5.9% and 3.1%, respectively (P < .05). Among department chairs, only women and Asian faculty increased by 6.4% and 7.5%, respectively (P < .05). The proportion of women chairs increased from 10.0% (19 of 191) in 2006 to 17.4% (39 of 224) in 2017. Black and Hispanic chairs collectively represented less than 10% of the total chairs every year.

DISCUSSION: The significant percent annual increase in women faculty in academic ranks and chair positions suggests that the radiology faculty is becoming more diverse. However, the decreasing proportion of women with increasing academic ranks within each year of the study period suggests attrition or lack of promotion of women radiology faculty. The disparity in black and Hispanic faculty members and chairs suggests that emphasis should continue to be placed on tailored recruitment.

OBJECTIVE. The purpose of this article is to present strategies and guidelines that can be implemented in the performance of cross-sectional interventional procedures during the coronavirus disease (COVID-19) pandemic. CONCLUSION. Radiologists who perform cross-sectional interventional procedures can take several steps to minimize the risks to patients and radiology personnel, including screening referred patients to decide which procedures can be postponed, using appropriate personal protective equipment (PPE), minimizing the number of people involved in procedures, preserving PPE when possible, and applying proper room and equipment cleaning measures.